Device for controlled endoscopic penetration of injection needle

ABSTRACT

An endoscopic needle device comprises a handle and a catheter sheath connected to the handle, wherein the catheter sheath has at least one lumen, for example a needle lumen and a stabilization lumen, extending therethrough. A needle is selectively movable within the needle lumen between a needle retracted position and a needle extended position and a stabilization element is selectively movable within the stabilization lumen between a stabilizer retracted position and a stabilizer extended position. A linking mechanism may operatively connect the needle and the stabilization element so that when the needle is in the needle retracted position the stabilization element is in the stabilizer extended position and when the needle is in the needle extended position the stabilization element is in the stabilizer retracted position.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/006,530 filed Dec. 8, 2004, now U.S Pat. No. 7,402,163, which is acontinuation of U.S. application Ser. No. 10/459,615, filed Jun. 12,2003, now U.S Pat. No. 6,843,792, which is a continuation of U.S.application Ser. No. 10/083,467, filed on Feb. 27, 2002, now U.S Pat.No. 6,663,645, which is a continuation of U.S. application Ser. No.09/192,591, filed Nov. 17, 1998, now U.S Pat. No. 6,371,963, which areincorporated herein in their entirety.

FIELD OF THE INVENTION

The present invention relates to endoscopic needle devices, and inparticular relates to an endoscopic needle device allowing forcontrolled penetration of an injection needle.

BACKGROUND INFORMATION

Endoscopic needle devices are used for a variety of applications,including fine needle aspiration to collect cell cultures, injectionscelerotherapy to stop bleeding, and sub-mucosal injection of saline forEMR imaging. Current endoscopic needle devices used for these and otherpurposes typically consist of an actuation handle, a flexible cathetersheath, and a rigid metal needle. While current endoscopic needles aregenerally adequate for penetration of soft tissues, known devices mayhave difficulty penetrating tough lesions and tumors. Because theapplication of force by the operator occurs outside the body, the forcemay not be entirely transferred to the injection site. Accordingly, theneedle may be unable to apply enough pressure at the site to achievepenetration. Moreover, even if the needle does penetrate the site, thedepth of penetration cannot be readily controlled. For known embodimentsof endoscopic needle devices, this latter drawback exists for softtissue penetration as well as for harder tissues.

In addition, many lesions, tumors, or other injection sites arerelatively inaccessible or hard to reach. These sites may require somemanipulation or stabilization of the intended site. Known endoscopicneedle devices do not provide stabilization of the site to effectpenetration in many situations, much less stabilization that would allowcontrolled penetration of the needle.

SUMMARY OF THE INVENTION

In an exemplary embodiment, the present invention is directed to anendoscopic needle device, comprising a handle and a catheter sheathconnected to the handle, wherein the catheter sheath has at least onelumen extending therethrough. A needle is selectively movable within thelumen between a needle retracted position and a needle extended positionand a stabilization element is selectively movable within the lumenbetween a stabilizer retracted position and a stabilizer extendedposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an exemplary embodiment of an endoscopic needledevice according to the present invention, including a first exemplaryembodiment of a stabilization element according to the presentinvention;

FIG. 2 is a side view of a second exemplary embodiment of an endoscopicneedle device according to the present invention;

FIG. 3 is a side view of a third exemplary embodiment of an endoscopicneedle device according to the present invention;

FIG. 4 is a side view of a fourth exemplary embodiment of an endoscopicneedle device according to the present invention;

FIG. 5 is a side view of a distal end of the endoscopic needle device ofFIG. 1 including a second exemplary embodiment of a stabilizationelement according to the present invention;

FIG. 6 is a side view of a distal end of the endoscopic needle device ofFIG. 1 including a third exemplary embodiment of a stabilization elementaccording to the present invention;

FIG. 7 is a side view of a distal end of the endoscopic needle device ofFIG. 1 at a penetration site, with the stabilization element of FIG. 1in an extended position;

FIG. 8 is a side view of the distal end of the endoscopic needle deviceof FIG. 1 at a penetration site, with the stabilization element of FIG.1 in a retracted position;

FIG. 9 is a side view of a fifth embodiment of the endoscopic needledevice according to the present invention including a fourth exemplaryembodiment of a stabilization element according to the presentinvention;

FIG. 10 is a side view of an exemplary embodiment of a valve arrangementand linking mechanism for the needle device of FIG. 9;

FIG. 11 is a side view of the endoscopic needle device of FIG. 9 beingemployed to penetrate a lesion;

FIG. 12 is a side view of a distal end of the endoscopic needle deviceof FIG. 1 including a fifth exemplary embodiment of a stabilizationelement according to the present invention; and

FIG. 13 is a side view of a sixth exemplary embodiment of a needlepenetration device according to the present invention having anexemplary embodiment of a needle penetration window according to thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an exemplary endoscopic needle device 101 accordingto the present invention. The needle device 101 includes, for example, ahandle 103 connected to a catheter sheath 105 (the term catheter sheathis intended to include any sort of catheter or similar tubular member).The catheter sheath 105, which extends from a proximal end coupled tothe handle 103 to a distal end, will typically be a flexible member, butmay be completely or partially rigid if suitable. The catheter sheath105 has at least one lumen extending therethrough. In the exemplaryembodiment of FIG. 1, the catheter sheath 105 includes, for example, apair of lumens extending axially therethrough, a needle lumen 127 and astabilization lumen 125. The needle lumen 127 and stabilization lumen125 terminate at openings located, for example, at the distal end of thecatheter sheath 105 (the distal end being located to the right in eachof the Figures).

A needle 107 extends, for example, through the needle lumen 127 from aneedle base 115 disposed in the handle 103, to a needle head 111 which,in an extended position, protrudes from the distal end of the needlelumen 127. In a retracted position, the needle head 111 may becompletely received within the needle lumen 127. A needle hub 121 mayalso be attached to the needle 107 at, for example, the needle base 115.The needle hub 121 is disposed, for example, outside the proximal end ofthe handle 103. Inside the handle 103, the needle 107 may be retained inplace by retaining members 123. Those skilled in the art will understandthat alternate arrangements may be used to retain the needle 107 inconjunction with or in place of retaining members 123.

A stabilization wire 108 is provided, for example, within thestabilization lumen 125. The stabilization wire 108 extends, forexample, from a wire base 113 disposed in the handle 103, to astabilizing element which, in an extended position, protrudes from thedistal end of the stabilization lumen 125. In a retracted position, thestabilizing element may be completely received within the stabilizationlumen 125, if suitable. In the exemplary embodiment of FIG. 1, thestabilizing element is in the form of a loop 109 which is shaped, forexample, as a circular or ovoid wire element which, in an operativeposition, is placed around an injection site. Loop 109 may be formed,for example, by bending an extension of the stabilization wire 108 backaround upon itself and attaching the extension to the stabilization wire108. Those skilled in the art will understand, however, that anysuitable stabilizing element or elements may be used, and that thepresent invention should not be limited to the embodiments pictured inthe Figures and described herein. Likewise, in FIG. 1 the stabilizationlumen 125 extends into the handle, but other means of retaining thestabilization wire 108 inside the stabilization lumen 125 may beemployed.

In the exemplary embodiment of FIG. 1, needle 107 and stabilization wire108 are, for example, linked by a linking mechanism, although thelinking mechanism may be omitted in other embodiments, including severalembodiments described below. When present, the linking mechanismcoordinates the movement of the needle 107 and stabilization wire 108 sothat as one of the two elements is extended the other of the elementsretracts, for example by a corresponding amount. Any suitable linkingmechanism may be employed. In the embodiment of FIG. 1, for example,needle base 115 and wire base 113 have teeth extending along inner sidesthereof (i.e., the sides facing each other). The teeth interconnect, forexample, with gear 117. In this manner, needle base 115, wire base 113,and gear 117 form a rack-and-pinion arrangement that provides smooth,controlled movement of the needle 107 and stabilization wire 108 wherebymotion of the needle by a predetermined distance proximally causes acorresponding motion of the stabilization element distally with theratio of motion being determined based on the distance between the teethof the needle base 115 as compared to the distance between the teeth ofthe wire base 113.

At least one of the needle base 115 and the wire base 113 may extendoutside the handle 103, or be connected to a component which is outsidethe handle 103, so that the needle 107 and stabilization wire 108 may beeasily manipulated by the operator. In the exemplary embodiment of FIG.1, the wire base 113 is connected to a control tab 119. The control tab119 may be shaped, for example, in the form of a thumb loop designed tofit around the thumb of the operator. When the control tab 119 is urgeddistally by the operator, the stabilization wire 108 (along with thestabilizing element) will extend distally (assuming, for example, thatthe control tab 119 is attached to the wire base 113). At the same time,if a linking element is present then the needle 107 and needle head 111will retract, i.e. move proximally, into the needle lumen 127.

FIG. 2 illustrates a second exemplary embodiment of a needle device 101according to the present invention in which only a single lumen isprovided. It should be understood that the needle 107 and thestabilization wire 108 need not be maintained in separate lumens.Rather, in certain situations it will be advantageous for the needle 107and stabilization wire 108 to be located within a single lumen. This maybe true, for example, when very narrow vessels or body lumens whereinthe profile size of a deployed endoscope may be small, requiringinstrumentation and, correspondingly, a catheter sheath 105 havingrelatively thin cross-sections. As can be seen in FIG. 2, a needledevice 101 according to this embodiment of the present invention issimilar to the embodiment of FIG. 1. However, the exemplary embodimentof FIG. 2 includes a single lumen 126 in which the needle 107 andstabilization wire 108 are maintained. It may be seen that the cathetersheath 105 of the embodiment of FIG. 2 is of smaller cross-section thanthe catheter sheath of FIG. 1, but this is not required. In general, thecatheter sheath 105 in any embodiment may be of any suitable width. Itshould also be understood that while the remaining Figures typicallyillustrate a dual-lumen arrangement, a single-lumen arrangement may beemployed with other embodiments of the present invention, including theexemplary embodiments described below.

FIG. 3 illustrates a third exemplary embodiment of a needle device 101according to the present invention. In this embodiment, movement of theneedle 107 and stabilization wire 108 are, for example, not linked.Rather, the needle 107 and stabilization wire 108 may be activatedindependently, each being movable to any position regardless of theposition of the other. Accordingly, needle base 115 and wire base 113(if present) do not, for example, contain any teeth.

In some situations it may be preferable to provide partial linkagebetween the needle 107 and stabilization wire 108. In the exemplaryembodiment of FIG. 4, for example, the needle base 115 and wire base 113are provided with teeth along a portion of an inner side. In thismanner, stabilization wire 108 can be partially retracted, or needle 107partially extended, without causing movement of the other member. Whenthe stabilization wire 108 or needle 107 reaches a certain point,however, the teeth of the wire base 113 or needle base 115 contact, forexample, gear 117. If the other of the wire base 113 and needle base 115is also contacting the gear, it will move in the direction oppositemovement of the first element.

As noted above, any suitable stabilizing element may be employed. FIGS.5 and 6 illustrate additional embodiments of stabilizing elements thatmay be used in conjunction with the present invention. FIGS. 5 and 6each illustrate the distal end portion of a needle device according tothe present invention, including, for example, needle lumen 127, needle107 with needle head 111, stabilization lumen 128, and stabilizationwire 108. FIG. 5 illustrates a stabilization element in the shape of abarb 139. The barb 139 may be shaped, for example, as a longitudinalmember having one or more backward facing barb elements. The barb 139may be used, for example, to puncture the injection site. When thestabilization wire 108 and barb 139 are retracted, the barb elementswill embed in the site and draw the site towards the needle device 101.Alternatively, the barb 139 may be, for example, scraped against theinjection site to draw the site towards the needle device 101.

FIG. 6 illustrates a third exemplary embodiment of a stabilizationmember according to the present invention. The stabilizing member ofFIG. 6 is shaped, for example, as a J-hook 149. The J-hook 149 may beextended, for example, beyond and around an injection site. Whenretracted, the J-hook 149 will wrap around, and possibly puncture, theinjection site, thereby achieving a stable hold on the site. Thoseskilled in the art will understand that the J-hook 149 may also includeone or more barb elements as shown in FIG. 5 to provide additionalstabilization.

FIGS. 7 and 8 illustrate the operation of the needle device 101 of FIG.1 in greater detail. The operation is illustrated with the needle deviceemploying, for example, a loop 109 as the stabilization element. FIG. 7shows the distal end of the needle device 101 with loop 109 in anextended position placed, for example, around an injection site.Assuming for example that a linkage mechanism is present, with the loop109 in the extended position, the needle 107 is in a retracted position.In this position, the needle head 111 may be contained entirely withinneedle lumen 127. However, those skilled in the art will understand thatother arrangements may be employed for shielding the needle head 111while the loop 109 is in the extended position.

Once the stabilization element is in place around the injection site andthe site is stabilized, loop 109 may be retracted. When the loop 109 isretracted, as shown in FIG. 8, the injection site is drawn towards theneedle device 101. At the same time, the needle 107 extends so that theneedle head 111 penetrates the injection site (again assuming linkage).The device may preferably be configured so that when the loop 109reaches a fully retracted position, the needle reaches a fully extendedposition, in which the needle head 111 achieves its maximum penetrationof the injection site. Once suitable penetration has been achieved, theneedle 107 may be retracted (as shown in FIG. 7). Those skilled in theart will understand that the needle 107 and needle head 111 may beextended and retracted numerous times, so that, if desired, the needlehead 111 will penetrate the injection site numerous times. The loop 109may then be withdrawn from around the injection site, and the needledevice 101 may be removed.

Accordingly, a method of use of the needle device 101 according to thepresent invention includes, for example, the following steps. The needledevice 101 is inserted and delivered to the injection site. Once theneedle device 101 has been positioned at the injection site, thestabilization element is activated to stabilize the site. This mayinvolve looping a loop 109 or J-hook 149 around the site, scraping abarb 139 along the site or thrusting a barb 139 into the site,positioning a grasper around the site (as discussed below), applying avacuum to the site (as discussed below), or applying some other sort ofstabilization element. With the stabilization element activated, theneedle may be extended. If a linkage mechanism is present, then thepenetration site may be drawn towards the needle device 101 as theneedle 107 is extended. Finally, the injection site is penetrated by theneedle 107.

FIGS. 9 to 11 illustrate another exemplary embodiment of an endoscopicneedle device 101 according to the present invention. In thisembodiment, the needle device 101 includes a vacuum hood 159 as thestabilization element. The hood 159 is, for example, a substantiallycylindrical member having a substantially cylindrical channel 160therethrough. The interior diameter of the channel 160 is, for example,substantially equivalent to the outer diameter of catheter sheath 105.The proximal end of the hood 159 may then be placed over the distal endof the endoscopic needle device 101 or the catheter sheath 105, the twomembers being attached at the overlap section. If desired, the hood 159may instead be integral with the needle device 101 or catheter sheath105 rather than a separate, attached member. The hood 159 is arranged,for example, so that the needle head 111 may extend into the channel 160of the hood 159 when in the extended position.

As shown in FIG. 11, the stabilization lumen 125 of this embodiment neednot contain any stabilization wire 108 or stabilization member. Rather,the stabilization lumen 125 may simply be connected to a vacuum (notshown), so that a vacuum can be drawn through the channel 160. The termvacuum is intended to include a partial or full vacuum, as well as anyvacuum-creating device, system, or arrangement that may be connected tothe stabilization lumen 125 to create a partial or full vacuum therein.The vacuum may be linked to the extension of the needle 107 (for examplevia a piston or valve arrangement) or may be controlled independently ofthe needle 107. In either case, the control tab 119 is not connected tothe wire base 113 in this embodiment, but instead is connected, forexample, to a vacuum base 166 as shown in FIG. 10 or to the needle base115. The vacuum base 166 may, for example, have the same orsubstantially the same shape as wire base 113.

An exemplary valve arrangement for connecting the stabilization lumen125 to a vacuum is shown in FIG. 10. The arrangement includes a vacuumbase 166 connected to a piston 162. The vacuum base 166 may be connectedto a control tab 119, and may form part of a linking mechanism, asdescribed above with respect to wire base 113. Vacuum base 166 andpiston 162 are movable, for example, between extended and retractedpositions. In the extended position, the piston 162 blocks vacuum lumen164 which is connected to a vacuum. Thus in this position no vacuum isestablished in the stabilization lumen 125 or vacuum hood 159. In theretracted position, however, the piston 162 does not block the vacuumlumen 164. In this position, a vacuum will be established in thestabilization lumen 125 and vacuum hood 159, drawing the injection siteinto channel 160. Those skilled in the art will understand that thevacuum lumen 164 or the connection between vacuum lumen 164 andstabilization lumen 125 may be shaped (e.g. widened) so that as thepiston 162 is retracted a vacuum is gradually established in thestabilization lumen 125 and vacuum hood 159.

In operation, the needle device 101 with vacuum hood 159 is extended tothe desired injection site. Once at the site, the vacuum may be appliedto draw the injection site into the channel 160, as shown in FIG. 11. Asthe vacuum is applied, or after the vacuum has been applied, the needle107 may be extended so that the needle head 111 enters the channel 160and penetrates the injection site. Once the needle head 111 hasadequately penetrated the site, the needle 107 can be retracted and thevacuum terminated. The needle device 101 may then be removed from thesite. As in the embodiments described above, it will be understood thatthe needle head 107 may be extended and retracted a number of timesprior to the removal of the needle device 101

FIG. 12 illustrates another exemplary embodiment of a stabilizationelement in operation. In this embodiment, the stabilization element,generally referred to as a grasper 169, includes, for example, aplurality of longitudinal hook elements 170 extending distally from theneedle device 101. The hook elements 170 extend substantially axiallyfrom the stabilization wire 108, but in an unbiased position also extendslightly radially outwardly as they extend distally, as shown in FIG.12. When retracted into the stabilization lumen 125, for example, thehook elements 170 may be forced inwardly so that all of the hookelements 170 fit inside the stabilization lumen 125. When extendedoutside the stabilization lumen, however, the hook elements may springback to their slightly outwardly extending position.

The distal tips of hook elements 170 bend back inwardly and proximally,for example, toward the needle device 101. When grasper 169 is extendedover an injection site, the hook elements 170 are urged outwardly by thetissue of the injection site. The hook elements 170 therefore exert aninward force on the injection site so that the bent tips of the hookelements 170 frictionally engage or puncture the injection site, asshown in FIG. 12. The grasper 169 may then be retracted to draw theinjection site toward the needle device 101. At the same time, needle107 may be extended until needle head 111 penetrates the injection site.As with the embodiments described above, the needle 107 may be extendedand retracted multiple times, if desired. After sufficient penetrationhas been achieved, the grasper 169 may be separated from the injectionsite (for example by twisting), and the needle device 101 withdrawn.

FIG. 13 illustrates a further exemplary feature of a needle device 101according to the present invention. In this embodiment, the handle 103includes, for example, a penetration window 133. The penetration window133 provides an operator with visual access to, for example, the needlebase 115, the needle itself, or another component connected to theneedle that may act as a visual depth gauge. In this embodiment, theneedle 107 may extend, for example, through a longitudinal channel inthe needle base 115 to the needle hub 121. The outer surface of theneedle 107 and the inner surface of needle base 115 may be threaded, forexample. When the needle hub 121 is rotated, the needle 107 and needlehub 121 move, for example, proximally or distally with respect to theneedle base 115, depending on which direction the needle hub 121 isrotated.

In this manner, a maximum penetration depth may be established for theneedle head 111. This maximum penetration depth may be adjusted, forexample, by rotating the needle hub 121 until the desired depth has beenestablished. The maximum penetration depth may be determined, forexample, according to the position of the depth gauge in relation to aset of penetration depth markers 137 appearing on the outside of thehandle 103. The depth markers 137 may be arranged so that when theneedle 107 is in an initial position, for example the fully retractedposition, the position of the needle base 115 relative to the depthmarkers 137 indicates, for example, the maximum penetration depth ofneedle head 111.

It may be understood that other arrangements of the needle 107 and theneedle hub 121 will allow for adjustment of the needle 107. For example,the needle hub 121 may be fixed to the needle base 115 or handle 103,for example, with respect to the axial direction (i.e. capable ofrotational but not axial movement). The needle hub 121 may also include,for example, a channel therethrough having threads on an inner surfacethat cooperate with threads on a threaded portion of the needle 107.When the needle hub 121 is rotated, the needle 107 will be extended orretracted, thereby altering the maximum penetration depth. Thisembodiment may or may not include a needle base 115 or other elementsdescribed above.

Although the present invention has been described with respect toseveral exemplary embodiments, those skilled in the art will understandthat there are many other variations of the above described embodimentswithin the teaching of the present invention, which is to be limitedonly by the claims appended hereto.

1. A method of injecting a needle into an injection site, comprising:inserting a needle device into a body, the needle device including: ahandle; a catheter sheath connected to the handle, the catheter sheathhaving a longitudinal axis; a stabilization element disposed at thedistal end of the needle device, the stabilization element having alongitudinal axis; and a needle disposed at the distal end of the needledevice, the needle having a longitudinal axis, wherein the longitudinalaxis of the stabilization element is parallel to the longitudinal axisof the needle, and wherein the longitudinal axis of the stabilizationelement and the longitudinal axis of the needle are both offset from thelongitudinal axis of the catheter sheath; delivering a distal end of theneedle device to an injection site; and adjusting at least one of thestabilization element and the needle to control penetration of thetissue at the injection site by the needle while using the stabilizationelement to hold the tissue at the injection site, wherein the step ofadjusting the needle to control the penetration of the tissue comprisesrotating a needle hub engaged with a surface of the needle.
 2. Themethod according to claim 1, wherein the needle hub includes a threadedsurface for engaging an outer surface of the needle that is threadablycoupled to the threaded surface.
 3. The method according to claim 2,wherein rotating the needle hub in a first direction moves the needledistally to increase the depth of the penetration of the needle; andwherein rotating the needle hub in a second direction opposite the firstdirection moves the needle proximally to decrease the depth of thepenetration of the needle.
 4. The method according to claim 1, furthercomprising determining the depth of the penetration of the tissue at theinjection site by the needle and adjusting one of the stabilizationelement and the needle based on the depth of penetration of the tissueat the injection site.
 5. The method according to claim 1, wherein thestep of adjusting one of the stabilization element and the needle overat least a part of a range of movement in a first direction causes theother of the stabilization element and the needle to move in a seconddirection opposite the first direction.
 6. A method of injecting aneedle into an injection site, comprising: inserting a needle deviceinto a body, the needle device including: a handle; a catheter sheathconnected to the handle, the catheter sheath having a longitudinal axis;a stabilization element disposed at the distal end of the needle device,the stabilization element having a longitudinal axis; and a needledisposed at the distal end of the needle device, the needle having alongitudinal axis, wherein the longitudinal axis of the stabilizationelement is parallel to the longitudinal axis of the needle, and whereinthe longitudinal axis of the stabilization element and the longitudinalaxis of the needle are both offset from the longitudinal axis of thecatheter sheath; delivering a distal end of the needle device to aninjection site; applying the stabilization element to hold tissue at theinjection site; penetrating tissue at the injection site with the needlewhile using the stabilization element to hold the tissue at theinjection site; and determining the depth of the penetration of thetissue at the injection site by the needle using a measurementmechanism.
 7. The method according to claim 6, wherein the measurementmechanism is a depth gauge.
 8. The method according to claim 7, whereinthe step of determining the depth of penetration of the tissue at theinjection site comprises determining the depth of penetration based onthe position of the depth gauge in relation to depth markers located onthe handle.
 9. The method according to claim 6, further comprisingadjusting at least one of the stabilization element and the needle tocontrol the penetration of the tissue at the injection site by theneedle, based on the determination of the depth of penetration of thetissue at the injection site.
 10. The method according to claim 9,wherein the step of adjusting the needle to control the penetration ofthe tissue comprises rotating a needle hub coupled to the needle in afirst direction to increase the depth of the penetration of the needle;and rotating the needle hub in a second direction opposite the firstdirection to decrease the depth of the penetration of the needle. 11.The method according to claim 9, wherein the step of adjusting thestabilization element to control penetration of the tissue comprisesactuating a control tab.
 12. A method of injecting a needle into aninjection site, comprising: inserting a needle device into a body, theneedle device including: a handle, a catheter sheath connected to thehandle, the catheter sheath having a longitudinal axis; a needle atleast partially disposed within the catheter sheath and axially movablerelative to the catheter sheath, the needle having a longitudinal axis;and a stabilization mechanism for holding tissue at an injection site,the stabilization mechanism having a longitudinal axis, wherein thelongitudinal axis of the needle is parallel to the longitudinal axis ofthe stabilization mechanism, and wherein the longitudinal axis of thestabilization mechanism and the longitudinal axis of the needle are bothoffset from the longitudinal axis of the catheter sheath; delivering adistal end of the needle device to the injection site; stabilizingtissue at the injection site; and controlling penetration of tissue atthe injection site by the needle, wherein the step of controllingpenetration of tissue comprises drawing the injection site towards thecatheter sheath while simultaneously extending the needle distallyrelative to the catheter sheath to penetrate tissue at the injectionsite.
 13. A method of injecting a needle into an injection site,comprising: inserting a needle device into a body, the needle deviceincluding: a handle, a catheter sheath connected to the handle, whereinthe catheter sheath has a longitudinal axis; a needle at least partiallydisposed within the catheter sheath and axially movable relative to thecatheter sheath, the needle having a longitudinal axis; and astabilization mechanism for holding tissue at an injection site, thestabilization mechanism having a longitudinal axis, wherein thelongitudinal axis of the needle is parallel to the longitudinal axis ofthe stabilization mechanism, and wherein the longitudinal axis of thestabilization mechanism and the longitudinal axis of the needle are bothoffset from the longitudinal axis of the catheter sheath; delivering adistal end of the needle device to the injection site; stabilizingtissue at the injection site; controlling penetration of tissue at theinjection site by the needle, and monitoring the depth of penetration oftissue at the injection site by the needle.
 14. The method according toclaim 13, wherein the handle includes a depth gauge for indicating thedepth of penetration of the tissue at the injection site and a windowfor visualizing the depth gauge, and further comprising determining thedepth of penetration based on a position of the depth gauge within thewindow.
 15. The method according to claim 14, wherein the step ofcontrolling penetration of tissue comprises adjusting the position ofthe needle relative to the sheath based on the determination of thedepth of penetration.